One vertex per element, one color per generator, with an edge from x to x·s.
(9,10)(11,19)(12,17)(13,18)(14,15)(16,20)(21,24)(22,23)(25,26,31,36)(27,34,29,32)(28,38,39,33)(30,35,37,40)(1,2)(3,6)(4,7)(5,8)(11,20)(13,21)(16,19)(18,24)(25,27,31,29)(26,32,36,34)(28,30,39,37)(33,35,38,40)(1,3)(2,5)(4,8)(6,7)(9,11,15,20)(10,16,14,19)(12,21,23,13)(17,18,22,24)(25,28,31,39)(26,33,36,38)(27,37,29,30)(32,40,34,35)(3,8)(5,6)(9,12,15,23)(10,17,14,22)(11,13,20,21)(16,24,19,18)(25,29,31,27)(26,34,36,32)(28,30,39,37)(33,35,38,40)(1,3)(2,6)(4,8)(5,7)(9,13)(10,18)(11,12)(14,24)(15,21)(16,22)(17,19)(20,23)(25,30)(26,35)(27,28)(29,39)(31,37)(32,33)(34,38)(36,40) involution — undirected(1,2)(3,6)(4,7)(5,8)(9,14,15,10)(11,16,20,19)(12,22,23,17)(13,24,21,18)(25,26)(27,32)(28,33)(29,34)(30,35)(31,36)(37,40)(38,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.